Editor's Note: The ASCO Breakthrough Summit, co-hosted by the American Society of Clinical Oncology (ASCO), the Japanese Society of Clinical Oncology (JSCO), and the Japanese Society of Medical Oncology (JSMO), in collaboration with several authoritative societies in the Asia-Pacific region, including the Chinese Anti-Cancer Association (CACA) and the Chinese Society of Clinical Oncology (CSCO), was held from August 8-10 in Yokohama, Japan. This year’s conference featured two significant advances in prostate cancer research (Abstract Nos. 118 and 119), which are summarized below.01 Evolving Treatment Prospects for Metastatic Hormone-Sensitive Prostate Cancer: A Multicenter Study
This study utilized a multicenter database to retrospectively analyze patients with metastatic hormone-sensitive prostate cancer (mHSPC) who began treatment between February 2018 and June 2023. It explored the prospects and clinical outcomes of androgen receptor signaling inhibitors (ARSI) in the treatment of these patients. Various statistical methods were employed to assess the impact of ARSI combined with androgen deprivation therapy (ADT) versus combined androgen blockade (CAB) on oncological outcomes, and the incidence of adverse events was compared.
Key findings include:
- Among the 829 patients, 42.5% received ARSI combined with ADT, 44.0% received CAB, and 13.5% received ADT monotherapy.
- The use of ARSI combined with ADT has been increasing yearly.
- Compared to CAB, ARSI combined with ADT extended the time to progression to castration-resistant prostate cancer (CRPC) and prolonged progression-free survival 2 (PFS2).
- There was no significant difference in cancer-specific survival (CSS) and overall survival (OS) between the two treatment regimens.
- The incidence of grade 3/4 adverse events was 1.9% in the CAB group and 6.0% in the ARSI combined with ADT group.
The study concluded that for mHSPC patients, initial treatment with ARSI combined with ADT improves oncological outcomes compared to CAB, particularly in delaying the onset of CRPC and extending PFS2, and should be considered as the first-line treatment of choice. Although CAB and ADT monotherapy have fewer adverse events, the therapeutic advantage of ARSI combined with ADT makes it the recommended treatment option.
02 Cabazitaxel Treatment Outcomes and PSA Response in Metastatic Castration-Resistant Prostate Cancer (mCRPC) with Prior PSA Response to Docetaxel
This study evaluated the efficacy of cabazitaxel in patients with metastatic castration-resistant prostate cancer (mCRPC) who had previously received docetaxel treatment and sought to identify predictive factors influencing its efficacy. The study found that among patients treated with cabazitaxel, those who responded to docetaxel (achieving a PSA reduction of more than 50%, or PSA50) had a significantly higher likelihood of achieving PSA50 with subsequent cabazitaxel treatment. Specifically, patients who reached PSA50 during docetaxel treatment were 5.29 times more likely to achieve PSA50 during cabazitaxel treatment than those who did not achieve PSA50 with docetaxel.
However, the study also observed that there was no significant difference in overall survival (OS) with cabazitaxel treatment based on the PSA50 status during docetaxel treatment. The study included 80 patients with an average age of 70, 50% of whom achieved PSA50 during docetaxel treatment, but only 18.8% achieved PSA50 during cabazitaxel treatment.
The study results suggest that for patients who previously responded to docetaxel, cabazitaxel may be an effective subsequent treatment option. Physicians can consider the patient’s prior response to docetaxel when deciding whether to use cabazitaxel or consider alternative treatments for mCRPC patients.
